In Project Runway's first blacklight challenge, the designers have to create a look that sparkles not only in daylight, but under blacklights under the runway as well. Anxieties rise when the unusual materials leave many of the designers in the dark. Jaime King joins the judges this week.

The second Team Challenge of the season leads to tensions and tantrums as the designers are forced to work together to create three-piece collections for a SoHo pop-up shop; Kelly Osbourne returns as a guest judge.

The designers' loved ones arrive from home for emotional reunions, but drama quickly takes over when the clothiers discover their special visitors will also be their clients, and $50,000 is on the line. Guest judges: Olivia Culpo and Katia Beauchamp.

In Part 1 of the two-part Season 15 finale, Tim Gunn visits the designers at home, but not all of their creations impress him. The clothiers return to New York and try to wow the judges with three pieces from their collection. Guest judge: Michael Kors.